Flat-key lock.



J. ROCHE.

v FLAT KEY LOOK.

APPLIOA'IIOH rnnn nov. 20, 1aoa.

965,409. Patented July 26, 1910.

UNITED STATEd PATENT OFFlCE.

JAMES ROCHE, 0F TERRYVILLE, CONNECTICUT, ASSIGNOR TO EAGLE LOCK C0,, OF TERRYVILLE, CONNECTICUT, A CORPORATION.

FLAT-KEY LOCK.

Specification of Letters Patent.

Patented July 26, 1910.

Application filed November 20, 1909. Serial No. 529,107.

To all whom it may concern:

Be it known that I, JAMES RooHE, a citi- Zen of the United States, residing at Terryville, in the county of Litchfield and State of Connecticut, have invented a new and useful Improvement in Flat-Key Locks; and I do hereby declare the following, when taken in connection with the accompanying drawings and the numerals of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in

Figure l, a broken View in elevation of a lock constructed in accordance with my invention with a portion of the cap or cover broken away. Fig. 2 a view thereof in rear elevation showing a positioning-notch in the main or frame plate of the lock for the reception of the positioningnotch in the lead of the key. Fig. 3 an enlarged View of the lock in transverse section on the line ab of Fig. 1. Fig. 1 an enlarged view of the key showing the positioning-notch in its lead. Fig. 5 a broken view of the main or frame-plate of the lock, drawn to an enlarged scale to show the rounding of the corners of the positioning-notch.

My invention relates to an improvement in flat-key locks, the object being to insure the right engagement of the bitings of the flat keys of such looks with the tumblers thereof, regardless of those small variations which are unavoidable even in interchangeable machine-made structures.

With these ends in view my invention consists in a fiat-key for fiat-key locks, the said key being formed in its lead with a positioning-notch.

My invention further consists in the combination with the main or frame plate of a flat-key lock, the said plate being formed with a positioning-notch, of a fiat-key formed in its lead with a positioning-notch for coaction with the notch of the said plate, whereby the position of the key is established in the look by the coaction of these notches.

In carrying out my invention as herein shown, I form a positioning-notch 2 in the lead or centering terminal 3 of an ordinary fiat key 4: having bitings 5, and the usual clearance-notch 6 located at the base of the shank 7 of the how 8 of the key. The

positioning-notch 2, aforesaid, coacts with a positioning-notch 9 formed in the frame or main plate 10 of the lock and leading out of the circular opening 11 made therein for the reception of the shouldered inner trunnion-like end 12 of the rotary key-post 13 which is formed with a key-way 14 for the reception of the key the bitings 5 of which engage in the usual manner with the key-sweeps 15 of pivotal tumblers 16 having springs 17 and swinging upon a post 18 mounted in the plate 10 which also carries a post 19 with which the springs 17 engage.

The bolt 20 of the lock bears upon the inner face of the plate 10 and has its shank 21 formed with a slot 22 receiving the post 18 which thus assists in guiding the bolt upon which the said tumblers are superimposed. At its outer end the key-post 13 is formed with a circular head 29 through which the key-way 14.- passes, the said head 29 having bearing upon the inner face of an inwardly turned flange 23 at the outer end of the tube 24 the inner end of which is shouldered to be set into an opening 25 in the cover 26 which is riveted to the plate 10 which is furnished for that purpose with rivet holes 27.

It will be understood that when the key is introduced into the lock and turned therein the side walls of its positioning-notch 2 at once coact with the metal of the plate 10 immediately surrounding the circular opening 11 therein to position the key against endwise movement without interfering with its free rotation.

Under this construction the positioning of the keys in a series of such locks may be predetermined with such a high degree of accuracy that the variations in the locks may be disregarded for the reason that the only variations that can arise will be slight variations in the width of the slots 2 and in the thickness of the plate 10. These variations when they exist, will never be great enough to permit the key to be sufliciently moved longitudinally in the lock to allow the bitings 5 of the key to coact with any of the tumblers with which they were not designed to coact and vice versa. Whereas in looks as formerly constructed, in which the positioning of the key was determined by the clearance-notch 6 and the flange 23 of the tube 24, it was common either in pushing the key into the lock or in withdrawing it therefrom, to have its bitings 5 improperly coact with the tumblers 16, because the tubes will sometimes vary in length, either in initial construction or when swaged in place; because the lock-covers may vary in thickness, or be sprung more or less so as to increase or decrease the distance between the flange 23 and the tumblers 16, and because the riveting of the cover 26 to the plate may also disturb the distance of the parts in the lay-out of the lock. On the other hand, in my improved construction, as already described, variations may exist in a look without affecting the positioning of the key when the same is formed with a positioning-notch in its lead coacting with a positioning-notch in the main plate or other part on which the tumblers of the lock are mounted.

As shown in Fig. 5 the corners of the positioning-notch 9 are rounded as at 28 to prevent the key from catching as would likely occur if the corners were left sharp.

I claim 1. A flat key for use in flat key locks, the said key being formed in its lead with a positioning-notch for co-action with that part of the lock upon which the tumblers are mounted.

2. In a fiat key lock, the combination with the main or frame plate thereof, the said plate having the tumblers mounted upon it and having a positioning-notch, of a flat key formed with a positioning-notch in its lead to coact with the positioning-notch in the said plate.

3. In a flat key lock, the combination with a main or frame plate having a circular opening and a positioning-notch leading radially out of the said opening and having rounded corners, of a key post having its inner end journaled in the said opening and formed with a key-way which, when the post is turned, is brought into registration with the said positioning-notch, and a flat key formed with a positioning-notch in its lead to coact with the positioning-notch in the said plate.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

JAMES ROCHE. Witnesses:

O'rrs B. HoUGH, H. G. GLOW. 

